ICME期间磁暴的太阳风参数和极光沉降能量

基于1995-2004年ICME驱动的强烈磁暴(SA型)、强磁暴(SB型)和延迟型主相暴(SC型)三种磁暴类型,对1AU处太阳风动压、太阳风速度、行星际磁场、EK-L电场以及极光沉降能量进行时序叠加分析,并分别与-vBz耦合函数和Newell耦合函数进行对比.结果表明,三种磁暴在ICME到达前期的太阳风动压较稳定,背景太阳风、极光沉降能量、行星际磁场和磁层存在相对平静期. ICME到达前期SA型磁暴的背景太阳风速度、行星际磁场南向分量以及极光沉降能量的均值高于另外两种磁暴类型,这说明大型日冕物质抛射在ICME到达前就对行星际磁场、背景太阳风和HP产生了影响.磁暴急始后,SC型磁暴的EK-L电场斜率小,峰值延后且行星际磁场北向分量增强,这些都是磁暴主相延迟的表现,极光沉降能量随着行星际磁场转为南向而增加.

Solar Wind Parameters and Auroral Hemispheric Power of Magnetic Storm during ICME

Based on three types of ICME-driven magnetic storms, including fierceness magnetic storm (SA type), strong magnetic storm (SB type) and delayed main phase storm (SC type) from 1995 to 2004, temporal superposition of the solar wind speed, the electric field E_K-L, the interplanetary magnetic field and the auroral hemispheric power at the 1AU are conducted, and compared with the -vB_z coupling function and the Newell coupling function respectively. The results show that there is a relative quiet period of the solar wind, auroral hemispheric power, interplanetary magnetic field and magnetic layer in the early stage of ICME arrival. However, the background solar wind speed, the southward component of the interplanetary magnetic field and the auroral hemispheric power of the SA magnetic storm are higher than those of the other two magnetic storm types. It indicates that the large coronal mass ejection has an effect on the interplanetary magnetic field, the background solar wind, and HP before the ICME arrives. After the rapid start of the magnetic storm, the low slope, delayed peak of the E_K-L electric field of SC type magnetic storm and the northward component enhancement of the interplanetary magnetic field are the manifestations of the main phase delay of the magnetic storm.